1-(Benzo{8 b{9 thienylalkyl)piperidines

ABSTRACT

A group of benzthienyl compounds useful in the treatment of disorders and diseases of the cardiovascular system and/or in the treatment of superficial and deep allergic phenomena is described. These compounds are piperidine compounds linked by the nitrogen atom to a substituted or unsubstituted benzo(b)thienyl radical through the intermediary of a lower-alkylene radical. The piperidine ring is further substituted by an acylamino residue.

United States Patent [191 Cayalla et al.

1451 Oct. 14, 1975 l-(BENZO[B]THIENYLALKYL)PIPERI- DINES [75] Inventors: John Frederick Cavalla, Isleworth;

John Leheup Archibald, Windsor, both of England [73] Assignee: John Wyeth & Brother Ltd.,

Maidenhead, England [22] Filed: Nov. 15, 1974 [21] Appl. No.: 524,028

Related US. Application Data [63] Continuation-impart of Ser. No. 323,684, Jan. 15, 1973, abandoned, which is a continuation-impart of Ser. No. 175,345, Aug. 26, 1971, abandoned.

[52] US. CL. 260/293.57; 260/293.65; 260/293.76;

260/293.77; 260/295 Q; 260/295 AM;

1 260/330.5; 424/267 [51] Int. CI. C07D 211/58 [58] Field of Search 260/293.57

[56] References Cited UNITED STATES PATENTS 3,855,242 12/1974 Chapman et al 260/29357 OTHER PUBLICATIONS Chemical Abstracts, 69: 106,384t (1968), Campaigne et al.

Chemical Abstracts, 77: 34,3552 (1972), Archibald et al.

Chemical Abstracts, 79: 136,989t (1973), Archibald.

Primary ExaminerSherman D. Winters 57 ABSTRACT 2 Claims, No Drawings .1 1.-(BENZO[B.]THIENYLALKYL )PIPERIDINES This invention relates to novel benzthienyl compounds and this application is a continuation-in-part of our application Ser. No. 323,684 filed Jan. 15, 1973 in which ('6 represents benzo[b]-thienyl, A represents a lower alkylene radical of-l to 4 carbon atoms, R represents a radical selected from cyclohexyl, phenyl and phenyl substituted by lower alkyl, halogen, lower alk-' oxy or trifluoromethyl and the pharmaceutically acceptable acid addition salts thereof.

It isto be understood that the term alkylene used herein includes both straight and branched chain radicals. i

The compounds of formula (I) and the pharmaceutically acceptable acid addition salts thereof exhibit pharmacological activity particularly action on the cardiovascular system (such as anti-hypertensive and/or peripheral vasodilation and/or anti-anginal and/or antiarrhythmic activity), anti-histamine activity such as activity against superficial and deep allergic phenomena for example, Urticaria, Pruritus, Allergic Rhinitis, Anaphylactic shock and Asthma when tested on warmblooded animals.

In addition to having useful pharmacological proper ties as mentioned above the novel compounds of the invention are intermediates for the preparation of other compounds of formula I. The other compounds of the invention are also intermediates for the preparation of pharmacologically active compounds.

The benz[b]thienyl radical W may be a 3- benzo[b]thienyl radical. Examples of R are unsubstituted phenyl or phenyl substituted by one or more groups, whichmaybe the same or .different selected from halogen (for example fluorine, chlorine or bromine), lower alkyl (for example methyl, ethyl, propyl, or n, s and t-butyl), lower alkoxy (for example mepounds of formula (I) are included in the scope of the invention. 7

One method of preparation of compounds of general formula (1) comprises reacting a compound of the general formula HN (III) (VII) wherein B is a straight or branched chain alkenyl radical, preferably a vinyl radical to give a corresponding compound of formula (,I). wherein A is a straight or branched chain alkylene radical.

\ The compounds of general formulae (IV), and (VII) are known compounds or can be made following the methods known for preparing compounds of these types. The starting materials of general formula [II can generally be made by acylating a corresponding amino compound of the general formula:

(VIII) and reducing the ring system to the corresponding piperidine ring. The starting material of general formula III is preferably prepared by either (i) forming the oxime of an N-benzyl-4-piperidone, reducing to give the 4-amino compound, acylating the amino group and then hydrogenolysing the benzyl residue, or (ii) treat- 5 ing the pyridine of formula:

thoxy, ethoxy, propoxy or butoxy), trihaloalkyl (for example trifluoromethyl). I Examples of A are methlene, ethylene, propylene,

methylethylene and butylene. Examples of acid addition salts are those formed from inorganic and organic acids in particular pharmaceutically acceptable'acid NHCDR with a benzyl halide, for example benzyl chloride to give the quaternary salt, reducing with an alkali metal borohydride .to give the corresponding N-benzyltetrahydropyridine which is further subjected to concomitant debenzylation and reduction of the 3,4- double bond by catalytic hydrogenation, or (iii) catalytic hydrogenation of compound (IX) in the presence of acetic anhydride to give:

- I vent, ,for example xylene, and removing the water formed during the reaction by az eotrd'pic distillation. If -NHCOR (50 necessary, reactive substituent groups can be blocked f -'du ring a.reac tion andlreleased later.

5. The reactions outlinedabove usually are carried .out

and then selectively hydrolysing the acetyl group. i a v n which is n swhs reaction h A second general method of preparation of com- The st wh smmi sh a pounds of formula (l icom'prises reacting a compound yaries depehdmg'oh h Pamcular reactants being of formula (I) in which the NHCOR group is replaced ployed. If necessary heating the reactants solution under reflux can be carried out, and if necessary heatby a free amino group with either a reactive derivative i .b d of an acid of general formula R.COOH (where R is a munder ii may ft? g i b phenyl radical). As a reactive derivative of the acid of f h O genera a ee formula R.COOH used in the process described above, phreparel en 1 nzcessary i morehsu S fi b "2 we have found it preferable usually to use a halide (for t e may e convert-e Y to e S example the chloride or bromide) or an anhydrida each within its own meanings specified in connection Other examples of reactive derivatives of the acid wlth formula i R.COOH which maybe used are the acid azide mixed If a compound of e (I) pmquced wlth a anhydrides and active esters. Furthermore, the com- 3221; 1 :535 ggf g iig 5 a ii i g ggg pounds of g g i g i i g g a free amino group instead of NHCOR and the free i s gisc e ll 2y a ire: airii n gio llp with the sdig i group may E 22? 8 a P W' a r t t v R.COOH in the presence of a known Condens ng agent, ygg z gi g g spp (for example a carbodiimide), or by firstact'ivating the v the ra'dica'l has one or'mbfk mthoxysub 3:112: i$li$iff;.Z.1.;J.2?hifie' iifa 25 I compoundmay be brought a out 'nown manner. fig g gg i -f t ol:- g' Y Furthermore, if the radical W has nitro substituent m 0 e group h ersnce W this ma be reduced'in known manner to the correto :c f the Amino B e efl and spondinamino compound which in turn may be fur- I\)\;lgnel;Z7(8J20h8n8;h ;l:g cif;3S olnls.O 2I;nc .-i,Publi hers. 196l).at r g. faky gi l h- .b h d v ompou'n s o ormu a nw 1c" isa ranc e The Compounds of general r a may p I chain alkylene radidal possess an" asymmetric carbon pared y Starting with aeompouhd P formula: atom and are therefore capable'of existing in optically active stereo'i'someric forms: The optical isomers may I R.CUD'HN 1 Q N r. V a i r beseparated by standard resolution procedures. The

- of a catalyst for example Raney Nickel. An organicsolf,

N-A-T -A-T generally be resolved by treatment with a suitable optically active acid. Optically ac'tive acids are described in 1 r the literature and suitable ones for the resolution'of any XI (8) 5 XI b 40 particular compound are chosen by experiment.

- 1 If necessary, in any of the reactions hereinbefore dewherein T is a known precursor group of W and reacting with another molecule of the type known in the literature for. the formationv of W. Reference ,may be made in this connection v to standard, textbooks of Organic Chemistry by-Paul 'Karrer. (Elsevier Publishing Company, ,Inc., 1950); Organic Chemistry by Fieser & Fieser ,-.(Reinhold Publishing Corporation, 1956); Chemistry of CarbonCompounds by- Rodd (Elsevier), v Amsterdam, 1951-l969);-Heterocyclic Compounds edited by Elderfield (John Wiley & Sons, Inc.,

' during a reaction and released at a later stage. As already indicated the novelpiperidine compounds provided by the invention contain a basic nitrogen atom and thus can form acid addition salts-with acids (particularly pharmaceutically acceptable acids) or quaternary ammonium salts-,for exampl'e with alkyl halides or aralkyl halides (particularly methyl iodide or-benzyl chloride orbromide'). The' acid additionsalts may either be formed in situ during the hereinbefore de- 'scribed processes and'isolated therefrom or a free base and Chemistry of the Heteroeyehe may be treated with-the'appropriate acid in the pres- POunds edlted by welssherge'r (lhtersclehcei 4 ence of a suitable solvent and then the salt isolated. The

A still further aspect of the invention 18 the provision quaternary Salts may beprepared byytreating the free of a further Process for the Preparation of compounds base with the appropriate halidein the presence or abof general formula (1) consists of reacting a compound .Sence f asolvent V I 0f th general fofmulai The compounds of thezinvention may be formulated into pharmaceutical compositions which contain as ac- 1 j tive ingredients a compoundof formula (I) as hereinbefore defined, which may'bemicronised. In addition to Which and A have th a g dfiifihedflbove) I the-active ingredient said compositions alsocontain a with a compound Of formula I I v nontoxic carrier. Any suitable carrier known in the art The reaction is preferably carried out in thepresence can b d to preparg h pharmweuticaicomPosL tio ns. In composition, the.car rier. may.be a solid, vent, which is inert under the reaction conditions, liquid pr m xtur of ill li'q a d, li id s lid f r usually used for example xylene, toluene or'benzene. o sitigns n'clude"powders, tabletsand capsules. A Preferably the reaction is carried out by heating the resolid carriercan be oneor more substances which may compounds contain a' basici nitrogen atom and mayscribed, reactive substituent groups may be'blocked actants under reflux in a water-immiscible organic solalso act as flavouring agents, lubricants, solubilisers,

starch, gelatin, tragacanth, methyl cellulose, sodium carboxymethyl cellulose, a low melting wax, and cocoa butter. The term composition is intended to include the formulation of an active ingredient with encapsulating material as carrier to give a capsule in which the active ingredient (with or without other carriers) is surrounded by carrier, which is thus in association with it. Similarly cachets are included.

Sterile liquid form compositions include sterile solutions, suspensions, emulsions, syrups and elixirs. The active ingredient can be dissolved or suspended in a pharmaceutically acceptable sterile liquid carrier, such as sterile water, sterile organic solvent or a mixture of both. Preferably-a liquid carrier is one suitable for parenteral injection. Where the active ingredient is sufficiently soluble it can be dissolved in normal saline as a carrier; if it is too insoluble for this it can often be dissolved in a suitable organic solvent, for instance aque ous propylene glycol or polyethylene glycol solutions. Aqueous propylene glycol containing from 10 to 75% of the glycol by weight is generally suitable. In other instances compositions can be made by dispersing the finely-divided active ingredient in aqueous starch or sodium carboxymethylcellulose solution, or in a suitable oil, for instance arachis oil. Liquid pharmaceutical compositions which aresterile solutions or suspensions can be utilised by intramuscular, intraperitoneal or subcutaneous injection. In many instances a compound is orally active and can be administered orally either in liquid or solid composition form.

Preferably the pharmaceutical composition is in unit dosage form. In such form, the composition is subdivided in unit doses containing appropriate quantities of the active ingredient; the unit dosage form can be a packaged composition, the package containing specific quantities of compositions, for example packeted powders or vials or ampoules. The unit dosage form can be a capsule, cachet or tablet itself, or it can be the appropriate number of any of these in package form. The quantity of active ingredient in a unit dose of composition may be varied or adjusted from 5 mg. or less to 500 or more, according to the particular need and the activity of the active ingredient. The invention also includes the compounds in the absence of carrier where the compounds are in unit dosage form.

The following non-limiting examples illustrate the invention:

EXAMPLE 1 l-[2-(3-Benzo[b]thienyl)ethyl]-4- benzamidopiperidine a. 3'(2-Hydroxyethyl)benzo[b]thiophene (2.8 g.) in anhydrous pyridine (31 ml.)at l5C. was stirred while p-toluenesulphonyl chloride (3.29 g.) was added portionwise. One hour later, water was added, keeping the temperature below -l0C. The aqueous layer was decanted off and the residual oil was dissolved in methanol and kept at 0C. overnight, whereupon 3-(2- hydroxyethyl)benzo[b]thiophene, p-toluenesulphonate (1.71 g., m.p. 56-58C crystallised. (Found C,

61.3; H, 4.8. c,,n,,o,s, requires C, 61.4; H, 4.85%).

b. A mixture of the foregoing tosylate (1.25 g.), 4- benzamidopiperidine (0.77 g.) and potassium carbonate (l.04 g.) in isopropanol (19 ml.) was heated under reflux for 17 hours. The hot reaction mixture was fil' tered and the filtrate was allowed to cool. The resulting crystals were re-crystallised from ethanol made just acid with ethanolic hydrogen chloride to give the product hydrochloride hemihydrate, m.p. 242-245C. (Found: C, 64.4; H, 6.2; N, 7.1. C H N OS.HCL%H O requires C,64.45; H, 6.4; N, 6.8%)

The productexhibited hypotensive activity and also antihistamine activity.

EXAMPLE 2 1-(3-Benzo[b]thienylmethyl)-4- benzamidopiperidine I 3-(Hydroxymethyl)benzo[b]thiophene, p-toluenesulphonate is reacted with 4-benzamidopiperidine in the manner of Example 1 to obtain the title compound as the hydrochloride.

EXAMPLE 3 l-[4-( 3-Benzo[b]thienyl)butyl1-4- benzamidopiperidine 3-(4-Hydroxybutyl)benzo[b]thiophene, p-toluenesulphonate is reacted with 4-benzamidopiperidine in the manner of Example 1 to give the title compound as the hydrochloride.

EXAMPLE 4 l-[2-(3-Benzo[b]thienyl)ethyl]-4-(pmethyl)benzamidopiperidine 3-(2-Hydroxyethyl)benzo[b]thiophene, p-toluenesulphonate is reacted with 4-(pmethyl)benzamidopiperidine in the manner of Example 1 to give the title compound as the hydrochloride.

EXAMPLE 5 1-[2-(3-Benzo[b]thienyl)ethyl]-4-(pchloro)benzamidopiperidine 3-(2-Hydroxyethyl)benzo[b]thiophene, p-toluenesulphonate is reacted with 4-( pchloro)benzamidopiperidine in the manner of Example 1 to give the title compound as the hydrochloride.

EXAMPLE 6 l-[2-( 3-Benzo[b]thienyl )etliyl -4-( m-methoxy )benzamidopiperidine 3-(2-Hydroxyethyl)benzo[b]thiophene, p-toluenesulphonate is reacted with 4-(m-methoxy)b enzamidopiperidine in the manner of Example 1 to give the title compound as the hydrochloride.

EXAMPLE 7 l-( 3-Benzo[b]thienyl )ethyl-4-(o-trifluoromethyl)- benzamidopiperidine 3-(2-Hydroxyethyl)benzo[b]thiophene, p-toluenesulphonate is reacted with 4-(o-trifluoromethyl)benzamidopiperidine in the manner of Example 1 to give the title compound as hydrochloride.

EXAMPLE 8 l-(3-Benzo[b]thienyl)ethyl-4-cyclohexanecarbox amidopiperidine v 3-(2-Hydroxyethyl)benzo[b]thiophene, p-toluene sulphonate is reacted with 4-cyclohexanecarboxamidopiperidine in the manner of Example 1 to give the title compound as the hydrochloride.

Tests for actionon the cardiovascular system were conducted according to one of the following procedures:

Hypotensive and/or Anti-Hypertensive activity Method 1 (Rat) Rats were anaesthetised with pentobarbitone sodium (60 mg/kg) and the jugular vein, trachea and carotid Cats were anaesthetised with pentobarbitone sodium mg/kg) and the cephalic vein, femoral and carotid arteries and trachea were cannulated. The carotid cannula was introduced into the left ventricle and the femoral cannula into the aorta. Blood pressure and heart rate were recorded from the aortic cannula and left ventricular pressure from the carotid cannula. The test compounds were administered intravenously (OJ- 25.6 mg/kg).

Method 2 (hypertensive rats) Male or female rats are rendered hypertensive by applying a figure of 8 ligature around one kidney and contralateral nephrectomy. Blood pressure stabilises at a hypertensive level after 6 weeks. Systolic pressure is measured indirectly using a Decker Caudal Plethysmograph A control group of rate is run with each group treated with drug. Each group usually consists of six rats. Drugs are usually administered by the IP or oral routes. Pressures are read prior to drug administration and at 2 and 24 hours thereafter.

Antihistamine activity was determined by the method of Alps et al [Br.J.Pharmacol.l972, 44, 52-62] Activity in either method 1 (rats or cats) or method 2 was considered to indicate hypotensive activity.

We claim:

1. A benzthienyl compound of the formula:

NHCOR lWl-A- N in which 'wf represents benzo[b]thienyl, A represents a lower alkylene radical of l to 4 carbon atoms, R represents a radical selected from cyclohexyl, phenyl and phenyl substituted by lower alkyl, halogen, lower alkoxy or trifluoromethyl or a pharmaceutically acceptable acid addition salt thereof.

2. A compound'as claimed in claim 1, which is 1-[2- (3-benzo[b]-thienyl)ethyll-4-benzamido-piperidine or a pharmaceutically acceptable acid addition salt thereof. 

1. A BENZTHIENYL COMPOUND OF THE FORMULA
 2. A compound as claimed in claim 1, which is 1-(2-(3-benzo(b)-thienyl)ethyl)-4-benzamido-piperidine or a pharmaceutically acceptable acid addition salt thereof. 